With an increasingly strong demand for performance of a computing system in the market, a scale of the computing system becomes larger. Computing nodes in the computing system generally interconnect with each other using various types of interconnect interfaces. To adapt to importance of a service borne in the computing system, complexity of an interconnect protocol, and the like, in addition to meeting performance such as high bandwidth and low delay, an interconnect interface used in the computing system needs to have high reliability.
In the prior art, high reliability of an interconnect interface is generally ensured using a retransmission buffer retransmission technology. FIG. 1 is a schematic structural diagram of a retransmission manner of a retransmission Buffer in the prior art. As shown in FIG. 1, bidirectional communication is performed between chip A and chip B using a link. For example, chip A sends a packet to chip B. A transmit (TX) end of the link uses component A1 as a retransmission Buffer to back up the sent packet; component B2 is responsible for performing a cyclic redundancy check (CRC) on the received packet, and sending a check result (whether the packet is correctly received) to component B3; component B3 is a retransmission management module of chip B, and is used to maintain a to-be-received pointer (reptr), where the pointer is 0 after link initialization is completed, the reptr is increased by 1 each time one packet is correctly received, and after a maximum depth of the retransmission Buffer is reached, the pointer is reset to 0 for restarting accumulation. The Reptr pointer always points to a location of a next to-be-received packet in the retransmission Buffer of chip A. Component B3 is further used to initiate a retransmission request to chip A after a packet for which a CRC is incorrect is received, where the retransmission request carries a reptr recorded in chip B. Component A3 is a retransmission management module of chip A, and is responsible for driving, after receiving a retransmission request packet, a TX port to send to chip B again, a packet starting from an address of the reptr, so as to complete a retransmission procedure. For a packet for which a CRC check is correct, chip B adds acknowledgment information to a packet sent by a TX end of the chip B and sends the packet to chip A. Chip A releases corresponding space in the retransmission Buffer after receiving the acknowledgment information, so as to form a head pointer (hptr) in the retransmission Buffer to indicate an oldest address that has not been released in the retransmission Buffer.
However, the foregoing retransmission Buffer retransmission technology only assures a scenario in which a recoverable failure occasionally occurs in a link. In a scenario in which an unrecoverable failure occurs in a link, a system is suspended because a packet in the retransmission Buffer is not acknowledged by a counterpart. The system can continue to work only after the failure is manually removed and the link is reconnected, which cannot ensure reliability of an interconnect system.